I was looking for an OCR that can do license plates while the car is moving, for a hobby project. The image quality is less than perfect, the lighting is never very good, and as the camera is mounted on my side window, all plates have a perspective transformation applied (e.g., topline and baseline are essentially never parallel)

Tesseract fails miserably. Trying to help it, I have not found a good open source project that would consistently equalize color pictures to black-and-white - sometimes there's shadow on the plates that foils all simple attempts.

And yet, GCV needs no parameters, and seem to do this perfectly on images I've tried.

So, assuming I'm willing to put in the time - how do I build my own GCV -- even if it's just for the hobby use case of reading license plate (and the next stage: reading house numbers - which GCV does reasonably well, although it is a much much harder problem)